THE PLANT HUNTER

By CHRISTOPHER HALLOWELL

The teacher and student sit cross-legged, facing each other on the floor of the open-sided hut in Western Samoa. Behind them the rain forest rises to the pinnacle of a long-dormant volcano. Beneath the thatched roof, a gaggle of children intently watches the proceedings. The teacher is Salome Isofea, 30, a young healer who is demonstrating her art. The man opposite her, a Westerner named Paul Alan Cox, is no ordinary student. He is a botany professor and dean at Brigham Young University in Provo, Utah, a world specialist in medicinal plants and, far from least in this exotic setting, the paramount chief of the nearby village of Falealupo. To people here, he is known as Nafanua, in honor of a legendary Samoan warrior goddess who once saved the village from oppression and protected its forests.

Salome is explaining a traditional cure for pterygium, an eye affliction common to the tropics in which vision gradually becomes obscured as a layer of tissue encroaches over the cornea. The traditional cure used by healers is leaves of Centella asiatica, a ground-hugging vine, which Salome chews into a poultice, smears on a cloth and then places as a compress on the afflicted eye for three consecutive nights.

But before this can be done, Salome explains, there is another crucial part of the cure. Holding a coconut-shell bowl containing ashes, she flicks them in the direction of Cox, who is playing the patient. When he soberly asks why the ashes are necessary, she replies that they enhance "spiritual transmission" between healer and patient. "We Westerners have to suspend judgment at these times," says Cox. "Look at our own belief in doctors wearing white coats. In Western culture that uniform is comparable to the 'spiritual transmission' she sees in the use of ash."

Moments like this are typical of Cox's experience as he scours the world's flora in search of plants that will benefit Western medicine. Cox has spent years in Samoa interviewing or apprenticing himself to traditional healers. He has also traveled throughout the South Pacific, as well as in Southeast Asia, South America, East Africa and as far north as Sweden's Lapland. In Samoa alone, healers have led him and his colleagues to 74 medicinal plants that might prove useful.

Samoan healers concoct poultices and infusions from the leaves, bark and roots of local plants, using them for conditions that range from high fever to appendicitis. Among them are root of 'Ago (Curcuma longa) for rashes, leaves of the kuava tree (Psidium guajava) for diarrhea, and the bark of vavae (Ceiba pentandra) for asthma. Virtually all the healers are women who learned their art from their mothers, who in turn learned it from their mothers. Now knowledge of the recipes and their administration, even the location of the plants in the forests, is endangered as more and more daughters forgo the long filial apprenticeships in favor of using Western pills and ointments.

For this reason, the discovery of young practicing healers like Salome delights Cox, who believes that only people like her can prevent the loss of centuries of knowledge. If he can carry Salome's knowledge to the developed world in the form of plants whose myriad chemical compounds might help combat incurable diseases--notably cancer, AIDS and Alzheimer's--the impetus to save the Samoan rain forest, and all forests, will be that much stronger.

Fewer than 1% of the world's 265,000 flowering plants, most inhabiting equatorial regions, have been tested for their effectiveness against disease. "We haven't even scratched the surface--not even in our own backyard," says Jim Miller, director of the Missouri Botanical Garden's natural-products program. Yet nearly a quarter of prescription drugs sold in the U.S. are based on chemicals from just 40 plant species. Examples are abundant. Codeine and morphine are derived from poppies. Vincristine and vinblastine, isolated from the rosy periwinkle, help treat cancers, including Hodgkin's disease and some leukemias. Curare, taken from several lethal Amazonian plants and often used to tip hunting arrows, is used in drugs that bolster anesthesia. An extract of the snakeroot plant, reserpine, traditionally employed in Asia to counteract poisonous snake bite, is the basis of a number of tranquilizers and hypertension drugs. Taxol, a compound in the bark of the Pacific yew, is used to treat some cases of advanced ovarian and breast cancer.

The drive is intensifying to collect and screen more natural products for their medicinal effects. Says Gordon Cragg, chief of the National Cancer Institute's natural-products branch: "Nature produces chemicals that no chemist would ever dream of at the laboratory bench." All this is heartening for biologists and environmentalists concerned about the dwindling of the planet's biodiversity, mostly concentrated in a wide girdle around the equator. Human activity, from farming to logging and road building, is chewing at this girdle, driving countless species to extinction even before they have been discovered. "I see ethnobotany--the study of the relationship between people and plants--as the key to the preservation of this vast collection of species as well as a pathway to halting many diseases," says Cox.

Cox, 44, a Mormon, first came to Samoa in 1973, when he was assigned to the country for his two-year compulsory missionary service after he graduated from Brigham Young as a botany major. His father was a park ranger and his mother a wildlife and fisheries biologist; his grandfather created the Utah state park system; and his great-grandfather was a founder of Arbor Day. Cox naturally expected to end up involved in conservation, but his stint in Samoa surpassed all his expectations.

He was not only impressed by the far-reaching influence of botany that he witnessed--beginning with the scene of a Samoan fisherman using a plant to poison fish in a river--but he also learned to speak and write Samoan better than many Samoans. (A difficult language, Samoan in its most elegant form requires extensive knowledge of local ritual and legend.) Cox went on to earn a doctorate in biology at Harvard, then joined Brigham Young's faculty as a botanist studying plant physiology and pollination.

In 1984 Cox returned to Samoa as an ethnobotanist, propelled there by personal misfortune. That year, Cox's mother had died a long and painful death from cancer. After witnessing her suffering, Cox experienced a revelation of sorts. Well aware of the rich tradition of folk healing he had observed a decade earlier, he now hoped to find a cure for cancer. "I vowed I would do whatever I could to fight the disease that killed my mother," he writes in Nafanua: Saving the Samoan Rain Forest, a book being published this fall that recounts his work and life in Samoa.

This time he brought along his wife and four young children. The family settled on the island of Savai'i in the isolated village of Falealupo, the westernmost point of Western Samoa, one of the world's poorest countries (average annual per capita income: $100). Here, far from many of the Western influences of neighboring American Samoa, Cox felt he could learn about the plants and the healers who use them before both vanished.

Major technological advances in screening processes have helped Cox and other ethnobotanists immensely. Pharmacologists must analyze between 10,000 and 17,000 chemical compounds before finding one with the potential to be tested for efficacy in humans. Until recently, animal testing and clinical trials of a single drug required an average 12 years of research and cost up to $300 million. But initial screening can now be done in a matter of days without using animals. Molecular biologists are able to isolate enzymes that can trigger human diseases, then expose those enzymes to a plant's chemical compounds. If a plant extract blocks the action of a particular enzyme--say, one that promotes a skin inflammation--they know the plant has drug potential. By extracting specific chemicals from the leaves, roots or bark with a series of solvents and testing each sample individually, scientists can determine which of the plant's thousands of compounds actually blocks the enzyme.

As a result of these advances, about 100 U.S. companies are searching out plants. Drug companies and scientific institutions are collaborating on field research all over the globe, racing to study as many natural substances as possible before they, or the native people who use them, disappear. Some work with the handful of ethnobotanists like Cox to ferret out drug candidates based on their knowledge of indigenous peoples. Others use a broad-brush approach, mass-collecting plants whose chemical compounds might contribute to new drugs.

One of the most extensive prospecting efforts is the National Cancer Institute's, which is focusing on screening plants for compounds active against the AIDS virus and nine major types of cancer. Since 1986, the NCI has received samplings of thousands of different species from ethnobotanists as well as such institutions as the New York Botanical Garden, the Missouri Botanical Garden and the University of Illinois at Chicago.

In contrast to random collecting, Cox feels, ethnobotanical field research provides a far more streamlined way of locating plants that have medical potential. "Indigenous people have been testing plants on people for thousands of years," says Cox. More important, healers may alert ethnobotanists to nuances that random collecting could miss. Take Homalanthus nutans, a rain-forest tree whose bark Samoans have used for centuries as a cure for hepatitis. Cox quickly found that he could not just casually go into the forest and gather the bark because 1) there are two varieties of the tree, and the bark of only one is effective, and 2) only trees of a certain size produce the desired extract.

After Cox collected the proper bark samples, he sent them to the NCI in the mid-1980s for testing. One isolate, called prostratin, appeared to inhibit growth of the AIDS virus, at least in the test tube, leading the NCI to patent it. If prostratin should ever be developed and approved by the Food and Drug Administration, both the Western Samoan government and the citizens of Falealupo could be in for a windfall under a royalty arrangement that Cox worked out between both entities and the NCI.

Cox has located three other medically promising plants. Two of the plants, used by Samoans to control skin inflammations, are being investigated by a pharmaceutical firm. The third doubles the life span of infection-fighting T lymphocytes in the test tube; its effect in the human body is not yet known. Cox's family has already benefited from the anti-inflammatories. After his infant daughter Hillary came down with a skin infection that did not respond to Western ointments, a healer ground up some leaves; the resulting greenish goo made the infection disappear. When Cox's son Paul Matthew was stung by wasps, healers rubbed bark on the wounds, and the swelling vanished.

When Cox first arrived in his adopted village of 2,000, he put himself under the tutelage of a healer named Pela, now 82, who agreed to be his mentor. Recently, Pela introduced Cox to cures for eye diseases other than pterygium: a poultice of beach pea leaves for sun blindness, fluid from immature coconuts for general eye injury, and eye drops from a fern (Phymatosorus scolopendrium) as a treatment for cataracts. Cox heard two other healers from different villages verify this use of the fern, and he was exuberant. "When three healers all use the same thing for cataracts, it's like a dream come true," he exclaimed.

Cox is more than a healer's apprentice. He knows that if the rain forests of Samoa continue to disappear, hundreds of potential drugs hidden there may never be found. So he spends much of his time between Brigham Young semesters trying to preserve the acreage that remains. More than 80% of the lowland rain forest has already been logged. Cox's aim is to offer cash-poor Western Samoans an alternative to selling out to loggers.

Samoans have traditionally used the forest for hunting, collecting medicinal plants, harvesting wild fruits and cutting trees for their dugout canoes. In this crucible of nature and culture, Cox believes, lies hope for conservation and the future of ethnobotany. "We can't save the forest without saving the culture," he says, "and we can't save the culture without saving the forest."

In 1988, Falealupo almost lost its 30,000-acre forest. The government told the villagers to construct a new school. It would cost $65,000, and the village would have to foot the bill. Ironically--or tellingly--a logging company arrived in the village shortly afterward and offered to pay $65,000 for permission to cut down the forest. The villagers, their hand forced, submitted.

Cox intervened just in time. He offered to raise enough money by mortgaging his home in Utah. But while in the U.S. to make arrangements, he pleaded the case to his students and two Mormon businessmen. Within six weeks they had raised the money, and Cox, back in Samoa, formalized an agreement with the villagers to protect their forest for 50 years.

It was during this period that the villagers informed Cox that they wanted to name him heir to the goddess Nafanua. When he declined, fearing that the title would interfere with his research, the villagers refused to sign the preservation agreement. Cox relented. "Being a deity is not my cup of tea," he says, "but Nafanua stands for conservation and rain-forest ecology, so I said to them, 'O.K., I'll take the cards I've been dealt.'" Now chiefs and children alike respectfully address him as Nafanua.

As a result of this work, Cox and a chief who helped him shared one of the six prestigious Goldman Environmental Prizes for 1997. Each received $37,500. Since then Cox has expanded his preservation efforts by establishing the Seacology Foundation, based at Brigham Young. Some of the foundation's funding comes through Cox's ethnobotanical success with medicinally, or in this case cosmetically, valuable plants. When Nu Skin International, a Utah-based personal-care company, wanted to hire Cox as a consultant, he charged a $40,000 fee that he plowed into the foundation. He also asked Nu Skin and Nature's Way, another Utah cosmetics firm, each to match his Goldman Prize award. Subsequently, Nu Skin began using extracts of a plant with anti-inflammatory properties in a foot cream. Seacology receives 25[cents] for every tube of the cream sold.

The foundation has since provided money for the Western Samoan village of Tafua to preserve its 20,000-acre rain forest. It helped persuade Congress to authorize the National Park of American Samoa--about 10,000 acres of forest and 420 acres of coral reefs in the neighboring archipelago. And it has helped villages build schools, medical clinics and cisterns to catch rainfall, the main source of drinking water.

In Falealupo, the foundation paid for the construction of a series of connected platforms and a walkway 200 ft. high between two huge trees at the edge of the forest. Administered by villagers, the aerial complex has brought in about $1,000 a month from tourists and school groups since it opened, profit that the villagers use to maintain the forest. "This is the first time these people have made money from the forest without destroying it," says Cox. "If they keep making this kind of money and other villages hear about it, the forests will be saved."

Cox dreams that one day soon the people of Western Samoa will see the benefit of preserving not only the rain forests surrounding their villages but also the vast cloud forests that still cloak the sides of the volcanoes that form the spine of Savai'i. Here he hopes the villagers will agree to "make the biggest national park in the whole world," before the chain saws get there too. He wants them to become as excited about the project as he is, rather than have the impetus come from outside. Behind this goal lies a philosophy that runs through Cox's work: helping native people understand the wealth of their heritage so that they will want to preserve it rather than sell it. Since it's no less than Nafanua who is urging them on, that seems a reasonable goal.

--With reporting by Andrea Dorfman/New York

With reporting by Andrea Dorfman/New York